refactor: centralize ack reaction gating

src/channels/ack-reactions.ts

@@ -0,0 +1,27 @@
+export type AckReactionScope = "all" | "direct" | "group-all" | "group-mentions" | "off" | "none";
+
+export type AckReactionGateParams = {
+  scope: AckReactionScope | undefined;
+  isDirect: boolean;
+  isGroup: boolean;
+  isMentionableGroup: boolean;
+  requireMention: boolean;
+  canDetectMention: boolean;
+  effectiveWasMentioned: boolean;
+  shouldBypassMention?: boolean;
+};
+
+export function shouldAckReaction(params: AckReactionGateParams): boolean {
+  const scope = params.scope ?? "group-mentions";
+  if (scope === "off" || scope === "none") return false;
+  if (scope === "all") return true;
+  if (scope === "direct") return params.isDirect;
+  if (scope === "group-all") return params.isGroup;
+  if (scope === "group-mentions") {
+    if (!params.isMentionableGroup) return false;
+    if (!params.requireMention) return false;
+    if (!params.canDetectMention) return false;
+    return params.effectiveWasMentioned || params.shouldBypassMention === true;
+  }
+  return false;
+}